Method of utilizing resinous woods



Patented May 25,

UNITED srA 1am .scnononn, or menrson,

WISCONSIN, Assmnon r 0. r; nunerss LABORATORIES, A CORPORATION OF WISCONSIN.-

" METHOD OF UTILIZING BESINOUS WOODS He Drawing. Application filed Kay 25,

To all whom it may concern: Be it known that l, Anmn W. Scnonons, a citizen of the United States, residing at Madison, in the county of Dane, State of Wisconsin, have invented certain new and useful Improgvements in Methods of Utilizing Resinons Woods; and I do hereby declare the folldwing to he a full, clear, and exact description of the invention, such as will enable others skilled in the art to which is'appertains to make and use the same.

round wood pulp is manufactured by holding holts oi wood against a roughened revolving stone, the wood fibers being sep- 1 arated by mechanical action. Water is passed over the stoneto absorb the heat produced by friction and to carry away the detached fibers, Ordinarily 60,000 lbs, or more, of water are used in grinding a ton of I W pulp, this Water being run to Waste. Heretotore the wood .ground has been largely limited to-deciduous species and to those conifers having a. low resin content, such as spruce and halsam. Many species of coniiers, such as jack pine, longlieaf pine and loblolly pine contain fibers 'ghly suitable for the manufacture of paper, but their use has been limited on account of the high resin content of the wood. This resin has 30. the following distinct disadvantages: During the grinding process, the channels and other depressions the grinding stone be come filled "with a mixture of resin and pulp, gradually reducing the eficiency oi the stone 0 at andnecessitating frequent cleaning of the grinder. The power consumption is high and the output of fibers low. .Furthermore, the wood fibers obtained contain particles of adhering to them -more or less loosely, and when: this pulpis assed over the paper machine, the resin gra ually accumulates on the Fourdrinier wire, especially in passingover' the suction boxes. After the resm has accumulated to a certain extent on 4 the wire, piecesef 'resin become loose h'om the wire and'ndhene'm the pulp sheet, and:

' are over thefrolls where the heat of theirollsmelts the resin and causes the paper.

' adhere to the rolls} .This causes the sheet as a -a h u t of he P e of an agent having a solvent ,and emulsityacids mo. Serial no. scenic.

' make available for paper making purposes resin-bearing woods not heretofore generally used in that way. It is a further object to he recover the resin and make it usefulin the arts.

To attain the fore oing, and other objects hereinafter set fort (more at length, the liquor-used for cooling the grindin stone and carrying away the detached filers is not water, as in the common practice oi grinding spruce, but is an aqueous solution ing action on resin. This agent may be an alkali, such as caustic soda.

of so-called The average resin content pitchy' woods, or woods so high in resin as to be generally unsuited for use in the paper making art, is about seven per cent, though certain trees or port-ions of a tree may contain much larger amounts. Asa rule this seven per cent resinmontains from ten to twenty percent. volatile oil, the remainder consisting mainly of resin acids, the chief of which is ordinarily known as abietic acid. A

Accordingto one embodiment of the 'preS- 1 cut invention, the procedure is as follows: 250 lbs. of caustic Soda (NaOH) is added toss" 5000 lbs. of water to produce a solution. having a solvent and emulsifying action on resin. 'This solutionis run over the grinder stone while grinding pitchy woods, such as jack pine, longleaf pine, loblolly pine, and the like. As the pulp leaves the stone it is passed through squeeze rolls or over suitable apparatus to remove most of the liquor, this liquor being returned to the grindingchamher by a pump, or other suitable means, instead oi eing run to waste, as is usual grinder practice. The grinder liquor is thus recirculated until it becomes well charged with resinous material. The resin oiE'the wood combine with the caustic soda to form water soluble salts Excessive foaming can be prevented by the addition of a small amount of petroleum "distillate,

or other suitable reagent. A ten of @lii'y wood containing six per centof resin acids, or. lbs, w

require 16 lbs. of caustic soda for complete neutralization. But the I .1 l sodium resinate thus termed, being soap has detergent'or propertleqand I solution( As a result, recirculation of the solution can properly be protracted, even beyond the point at which all free alkali has been neutralized. r

The alkalinesolution is reused or recirculated through the grinder until so spent that it no longer exerts a proper solvent actionon the resin of the pitchy woodbeing ground. The solution is then drawn off and replaced by fresh solution.

The spent solution thus drawn off forms a valuable by-product of the paper making operation. Its content of alkali resinates and free resin may be used for sizing the pulp by mixing the solution with pulp in a heater and adding alum in the known manner. But preferably I recover the .resin and .resinatesin a concentrated condition by salting out through the addition of common salt to the solution. Also, the resin may be recovered in the free state from the speit liquors by precipitatingwith suitable ac1 s.

As this invention concerns itself with the handling of materials in a. large way, thought must be given to the cost of that agent which gives to the grinding water its solvent and emulsifying action on resin. Likewise, thought must be given to the loss of this agent at certain stages of the complete operation. The pulp as it leaves the squeeze rolls contains about sixty per cent of moisture.so that a. ton of pulp on the dry basis would carry away about 3000 lbs. of

the grinding solution. When afresh alkaline solution is being used in the grinder, the pulp will be carrying away a larger amount of alkali than could be permitted ordinarily. This loss of alkali can, however, be largely avoided by washing the pulp with water after it leaves the squeeze rolls and returning the wash water to the grinding chamber, as re uired to replacethe solution carried away y the pulp. The availability of cheap alkali, and other considerations of. a local character, will determine whether it is advisable to wash the pulp after it leaves the squeeze rolls, and if so, to what extent alkali and alkali resinate can be recovered profitably from that materiaL.

The amount of alkali to be used preparing a fresh solution havin the desired solvent and emulsifying action on the resin of pitchy woods may be varied between wide limits, and the proportions above given of 250 lbs. of caustic soda to 5000 lbs. of Water are but illustrative of good practice in this regard. Alkali's other than caustic soda can be used, suclras sodium carbonate, caustic potash, and ammonia, or in place of these alkalis, I can use the soluble alkali salts of,

resins. Likewise, T can use the alkali salts of fatty acids commonly known as soaps.

But whether I use an alkali or an alkali resinate, or a soluble soap, as the agent added to the grinder water to produce an aqueous solution having solvent and emulsifying action on the resins of pitchy woods, the resin of the wood is so taken care of by the solution that it does not clog the grind-- solution as a colloid or emulsion, the grind-' ing liquor can be recirculated until substantially spent, and then can be drawn off and .made to yield its resinous material in forms readily marketable.

In the claims the expression in the bolt as applied to wood is used to designate relatively large blocks or pieces of wood as commonly used in the art of preparing ground wood mechanical pulp. The expression does not cover small pieces of wood such as wood chips usually used in the chemical pulp art. I claim 2-- too 1. Ihe method of making mechanical pulp from resinous wood which comprises grinding the wood in the bolt and subjecting the disintegrated fibers during grinding to the action of an aqueous solution of'an agent having solvent and emulsifying action on" resin.

2. The method of making mechanical pulp from resinous woods, which consists in grinding the wood in the bolt in the presence of an aqueous solution of an agent having solvent and emulsifying action on resin, and recirculatingsaid solution through the grinder until the solution is well charged with resinous material, substantially as described.

3. The method of making mechanical pulp from resinous woods, which consists in grinding the wood in the bolt in the presence of an aqueous solution of an agent having solvent and emulsifying action on resin,

recirculating said. solution through the then recovering the resinous material from the solution so concentrated by salting out with sodium chloride.

5. The-method of making mechanical pulp from resinous wood, which comprises grinding the wood in the bolt and subjecting the disintegrated fibers during the grinding'to the action of an aqueous solution of caustic soda.

6. The methodof making mechanical pulp from resinous woods, which consists in grinding the wood in the presence of an aqueous solution of caustic soda and restraining foaming with a petroleum dis tillate. Y t

7. The method of makin mechanical pulp from resinous woods, w ich consists in grinding the wood in the bolt in the presence of an aqueous solution of an agent having solvent and emulsifying action on resin,

squeezing and washing the pulp so produced and delivering the wash water to theogrinder for solvent action on fresh pul and re circulating the grinder solution t rough the a grinder until it is well charged with resinous material, substantially as described.

8. The method of making mechanical pulp from resinous woods with recovery of resin, which consists in grinding the wood in the bolt in the presence of an aqueous solution of caustic soda, squeezin and wash ing the pulp so produced and de ivering the wash water to the grinder for solvent action on fresh pulp, recirculating the grinder solution through the grinder to increase the concentration ofresin therein and then recover ing the resinous material from the solution so concentrated. r

9. lfhe method of preparing with a grinding stone pulp suitable for paper making from wood having a high resin content, which comprises grinding the wood in the bolt and treating the pul with a solvent and emu si erthereby to dissolve and en'pllsify the resin set free by the 1 grinder.

10. The method ofpreparing pul suitabli for paper making from wood bo t having a high resin content, which consists in subjecting the fibers as they are disintegrated -to the action of a resin solvent and emulsifier.

In testimony whereof I ain'x my signature. ARLIE WILLIAM SCHORGER.

-as it is ground 

